lv 8.2 grab image

[reut]

Dear Nate
finally i suceed to run it, i change the while loop to continue if true. thank you for helping me through the process.
i still need to check up why the code doesnt follow the external trigger (1 fps, instead 4 fps). but the main thing behind me thanks to your help.
wish you all the best
Cheers,
Reut

[reut]

Hi There,

i would like to know if saving the data to png file make me loss data, is it compressing the file?

i ran the experiment and i found out that the picture saved in 1 mb instead 8, and the photo are including black and white lines that proof the loosing of data.

so what can i do to prevent it?

thanks

[Sappster]

Hi Reut,

PNG images are compressed but are considered "lossless" (term is used loosely). Here is some information about the format itself:

http://en.wikipedia.org/wiki/Portable_Network_Graphics

As for the lines you are seeing, have you tried diffent compression ratios?

[Nate.H]

Hi Reut,

The PNG file format stands for Portable Network Graphics format, and uses lossless compression. Because the png file format is lossless, if saved correctly, you should not see any changes in the image when opening it back up.

What program are you using to display the saved images? If you are saving 16-bit images, there may be some display problems. I would take a look at this forums post:

PNG files Distorted
http://forums.ni.com/ni/board/message?board.id=200&message.id=10229&requireLogin=False

Do you get the same black and white lines when saving in a different file format?

Best Regards,

~Nate

[reut]

Hi,
so if i understood right, the losseless compresion, does not loss the data it is just the PNG format?
well, i see the black white lines in the lv display (the monitor of the block diagram) and after in the display of the images by  using different option such as, GIMP, firefox, f-spot photo viewer.
i will try to save the images in different format, but i afraid it wont give me what i need (i need to use with 16 bit, as it described for PNG)
so what are my options?
Thanks again

[reut]

Hi Mark,
whad do you mean in the term "compression ratios", originaly i didnt plan on compress the file, its not god to the experiment that i planed. and where can i control and change the compression ratios?
thanks,
Reut

[reut]

Hi,
i just recheck another program in the LV that i am using with, and i found out that even when the saving procedure is with diffrent format i still get the black white lines in the display monitior of LV block
i dont know what does it mean

[Nate.H]

Dear Reut,

Because the black and white lines appear in the LabVIEW image display as well as in your saved files, it sounds to me like the problem is actually with the acquisition, rather than the compression and save side of your program.

Can you acquire successfully without any noise or corruption with one of the simple examples, say the High Level IMAQ Grab VI? If you can, then I would try saving one of those images to file with a .png file format. If this works, then there is a good chance that the problem is somewhere in how your VI is programmed

 If this is the case, then we need to figure out what is going on with your VI that is causing you to acquire images that include this noise.

Good luck with the troubleshooting, and let me know how it goes,

~Nate

[mb056145]

Hi Nate,

I'm actually thinking of doing something very similar to what reut was doing. I'd like to take many high-speed images with a camera, and save them to a disk. I've looked at reut's program, and the only differences between that program, and the program that I'd like to run is that I need to be able to change the shutter speed of the camera (although I believe that I can do this with a program called MAX), I'd like to be able to change the target directory (for some reason, if I change the directory with the reut program, the camera only takes 1 "frame" and stops), and I'd like to be able to save a file for each frame taken by the camera (I can only get the reut program to save 1 file.) I have LabVIEW version 8.5. If you could help me out in any way, then that would be greatly appreciated. I'll also start another thread and I'll title it, "LabVIEW 8.5 high-speed camera" if you'd like to post to that. Thanks!

[reut]

Hi there,
one suggestion is to change the while loop, by changing the stop condition to continue if tru, instead the stop
once you will change that you will be able to capture series of images.
second, as i know LAB View 5 can support in progrram of previous version
let me know how is it going...